The aim of the Clinical Adherence Core will be to enhance patient recruitment and maintain adherence to the chemoprevention regimen in the clinical studies (Projects 1, 2, and 3). The Adherence Core will use behavioral science strategies to enhance compliance of all enrolled patients and to identify and intervene with patients who may have special adherence problems. The strategies will include brief counseling, patient education materials and a newsletter. These strategies will address relevant behavioral variables such as perceived susceptibility, perceived seriousness, benefits of the intervention and reduction of barriers, self efficacy and altruism. The Core will train Adherence Coordinators in each of the RTOG and CCOP clinical research locations (Projects 1,2) and maintain frequent Core coordination and monitoring of recruitment and adherence. In Project 3, at M.D. Anderson, special clinical interviewing and counseling for leukoplakia patients will be provided to enhance adherence. In addition to enhancement of adherence, the Core will study differences between adherents and non-adherents. A six-factor heuristic model, developed by Gritz, et al. at the Jonsson Cancer Center, for describing the variables affecting adherence with cancer control regimens, will be used as a framework. Selected scales for measuring behavioral variables will be adapted from work by Atwood, et al. from the Colon Cancer Prevention Project at the Arizona Cancer Center. A discriminant analysis of the variables in the six-factor model will be used to develop a model of adherence for chemoprevention trials in aerodigestive cancer.